This application relates generally to biometric feature detection. More specifically, this application relates to spectral, spatial, and/or temporal detection of a biometric feature.
Fingerprint-based biometric sensors are used across a broad range of applications, from law enforcement and civil identification to commercial access control. They are even used in some consumer devices such as laptops and cellular telephones. In at least some of these applications, there is a general need in the art to know when a biometric feature is placed on the sensor and to detect when a foreign object, other than a biometric feature, is placed on the sensor or where a biometric feature is located relative to a target location.